Window = {}

Window.prototype = {x=0, y=0, width=100, height=100}

Window.mt = {}

function Window.new(o)
	 setmetatable(o, Window.mt)
	 return o
end

Window.mt.__index = function (table, key)
		  return Window.prototype[key]
end

w = Window.new{x=10, y=20}
print(w.width)